The goal of this SBIR program is to develop a new intravenous infusion device to increase the safety of anesthesia, particularly in elderly patients. The device will combine pharmacokinetically controlled drug delivery with mathematical modeling of the effects of age and pharmacokinetic interactions. The phase I trial will examine propofol and remifentanil, two drugs necessarily given by intravenous infusion that are representative of the two classes of drugs nearly always combined in anesthesia: hypnotics and opioids. Age adjusted pharmacokinetic models exist for both. The Phase I clinical trial will supplement this knowledge with important new information about the pharmacokinetic interaction between propofol and remifentanil, including the effect of age on the interaction. The models developed in Phase I will be encoded into software and prospectively tested in Phase II by anesthetizing surgical patients using infusions calculated from the age and interaction adjusted models. These data will permit refining the model, which will then be encoded into a commercial second-generation pharmacokinetically based intravenous anesthetic delivery system. This innovative device will permit the anesthesiologist to adjust the level of drug effect with increased simplicity, precision, and safety, while adding very minimal software development cost to the price of the infusion device. PROPOSED COMMERCIAL APPLICATIONS: The commercial application is the development of a new drug delivery device to increase the safety of intravenous anesthesia for all patients, and in particular elderly patients.